Hazards that may occur in a grain dryer, such as a dust explosion, fire, or other such events, are difficult to suppress because the grain and the attendant hazard are contained within the dryer. Some of these hazards may be fought by spraying water on the exterior of the grain dryer. This, however, does little to suppress the hazard at its source, i.e., within the dryer. Thus, these hazards can frequently escalate in severity, ultimately resulting in the destruction of the dryer. It can also expose operators and firefighters to unpredictable safety hazards. The invention provides an efficient and economical internal staged suppression system for suppressing a hazardous event in a grain dryer.